JPH03176866A - Rotary head type multichannel magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To reproduce a data without lacking in the data even against a large burst error by increasing the number of times for multiple recording of a data needed in high reliability at the time of recording the data and selecting the best data among them to use at the time of reproducing. CONSTITUTION:The subject device is constitutive of M-channel signal input terminals 5, M-channel output terminals 6, a signal processing circuit 7, a memory 8 for temporarily holding a signal, a recording amplifier 9, and regenerative amplifier and equalizer 10. Then, recording and reproducing are changed by a changeover switch 11, and a signal is recorded and reproduced on a magnetic tape by a recording and reproducing head 12. And, which input signal and how many multiple writes are controlled from the exterior by a controller 15. Thus, the number of times for multiple recording of a signal required in particular for its reliability among the inputted signals is increased, and at the time of reproducing, the best data among them is selected to be used. By this method, the data can be reproduced without lacking in its data even against a burst error.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotating gutter type magnetic recording and reproducing device that can record and reproduce signals of two or more channels on a magnetic tape using a helical scan method.

[Prior art] As a rotating throat type multi-channel magnetic recording and reproducing device,
For example, 8 mm video multi-track PCM audio is known. This 8mm video will be briefly explained below. FIG. 8 is a diagram showing the structure of an 8 mm video recording track, where 13 is a magnetic tape and 14 is a recording track. The recording track 14 includes a video trunk section 16 and a PCMC-audio track 7, and the video track section 16 records video signals and FM audio signals. In addition, the audio track section 17 has a sampling frequency of 31.5 KHz, a quantization bit of 8 bits, non-linear, and a CRC code as an error detection code.
The error correction method is a cross-interleave method using simple parity, and a two-channel PCM audio signal is recorded.

In addition, for 8 mm video, as shown in FIG. 9, a multi-track PCM is available in which the audio track section 17 is extended to the video track section 16 and a total of six tracks of PCM audio are recorded. In this case, the audio track section 17 is taken as trunk 1, and the video track section 16 is divided into five equal parts, with tracks 2 to 6 so that PCM audio equivalent to trunk 1 can be recorded on five tracks.

If you use this multi-track PCM, 6 tracks 12
Channel PCM audio can be recorded and played back.

[Problem to be solved by the invention]

Conventional multi-channel magnetic recording and reproducing devices are configured as described above, and use CRC codes and interleaving, so they can correct random errors, but they can also correct scratches on the tape and head. There is a problem in that large burst errors such as clogging cannot be corrected and data is lost.

This invention was made in order to solve the above-mentioned problems, and provides a rotating head type multi-channel magnetic recording and reproducing device that can reproduce data without dropping data even in the case of large burst errors. The purpose is to

[Means for Solving the Problems] A rotary head type multi-channel magnetic recording and reproducing device according to the present invention includes means for multiplex recording arbitrary input signals on a magnetic tape, and a storage means for temporarily retaining data. The number of times of multiplex recording is changed depending on the input signal, or multiple recording is performed over two or more tracks.

[Effect]

The rotary head type multi-channel magnetic recording/reproducing apparatus of the present invention increases the number of times of multiplex recording for signals that require particularly high reliability among input signals, and multiplex records over two or more tracks. By this,
Even in the case of burst errors such as scratches on the tape or clogging of the head, data can be reproduced without being lost.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a track pattern recorded on a magnetic tape by the N-channel magnetic recording/reproducing apparatus according to this embodiment. In the figure, a, bC and d are tracks scanned by different heads, respectively, 1a-Na and 1
b-Nb is a signal recording area in each trunk, and can record N channel signals.

In this embodiment, an example will be explained in which the input signal A is double-written and other signals are not multiplex-recorded.

FIG. 2 is a block diagram of the N-channel magnetic recording and reproducing apparatus according to this embodiment. In the figure, 5 is an M-channel signal input terminal, 6 is an M-channel output terminal, 7 is a signal processing circuit, and 8 is a signal input terminal. This is a memory that temporarily holds information. 9 is a recording amplifier, and 1o is a reproduction amplifier and equalizer.

11 is a switch that switches between recording and playback; 1
Reference numeral 2 denotes a recording/reproducing head for recording signals on a magnetic tape and reproducing signals. Reference numeral 15 denotes a controller which externally controls which input signals are written in multiple layers.

Fig. 3 is a diagram showing the relationship between the input signal, memory contents, and recorded signal when recording a signal, and Fig. 4 is a diagram showing the relationship between the reproduced signal, memory contents, and output signal when reproducing the signal. be.

Next, the operation will be explained with reference to FIG. When recording signals, signals A to C are first input from the input terminal 5. As shown in FIG. 3, the signals A are Al, A2 . A3. A
4..., signal B is Bl, B2, B3 . B4.
. . . etc. are input in this order. Among these signals, if the importance of the signal A is high and high reliability is required, the signal A is divided into two by control by the controller 15.
Avoid overwriting and overwriting other signals.

The input signal is temporarily held in the memory 8. Third
The figure shows how data is written to the memory 8. The memory 8 is divided into pieces, and first, the signals input in the interval tl are written as the signal A3 to the memory 3, the signal B3 to the memory 6, and so on. Next, the signals input in the interval t2 are written as signal A4 to memory 1, signal B4 to memory 4, and so on. Next, in the interval t3, the signal A5 is written to the memory 2, the signal B5 is written to the memory 5, etc., and
A4 held in memory 1 and A held in memory 3
B3, etc. held in the memory 6 are sent to the recording amplifier 9 in a time-division manner, and are recorded on the magnetic tape 13 through the changeover switch 11 and the recording/reproducing head 12. When the above steps are repeated and signals are recorded on the magnetic tape 13, a track pattern as shown in FIG. 1 is recorded on the magnetic tape 13. As shown in Figure 1,
In track a, signal A data is recorded in areas 1a and 3a, signal B is recorded in area 2a, etc., and so on, data for signal A that requires high reliability is written twice. There is. Also, regarding signal A, the data of A2 is stored in area 3a of track a and area 1b of track b...etc.
The same data is recorded on trunks scanned by different heads.

Next, the case of reproducing a signal will be explained.

A signal is reproduced from the magnetic tape 13 recorded as described above by the recording/reproducing head 12, and the changeover switch 11, reproduction amplifier, and equalizer 10. Data is temporarily held in memory 8 through signal processing circuit 7. FIG. 4 shows how data is written to the memory 8.

Divide the memory 8 into i pieces, and first, among the data of trunk a reproduced in the section sl, data A1 recorded in area 1a is transferred to memory 1, and data B1 recorded in area 2a is transferred to memory 7. , data A2 recorded in area 3a is written to memory 4, etc.

Next, in section 32, data A2 recorded in area 1b of track b is transferred to memory 2, data B2 recorded in area 2b is transferred to memory 8, and data A3 recorded in area 3b is transferred to memory 5. Write...etc.

Next, in section 83, each data is written to the memory, and among the double-written data of A, A2 of memory 2 and A2 of memory 4 are compared, and for example, the one with fewer errors is selected and output. A signal is output to the signal A output terminal of the terminals 5. At the same time, B2 held in memory 8
The data is also output as a signal from the signal B output terminal.

As mentioned above, when reproducing a signal, it is necessary to select one of the double-written A signals from the same signal recorded in two locations, depending on the signal reproduction status, the number of errors, etc. Therefore, reliability can be improved. Also, the double-written A signal is recorded in recording areas 1 and 3 on the track.
Therefore, even if the digital data in one area cannot be reproduced due to a scratch or the like occurring in the running direction of the tape, if the digital data in the remaining area can be reproduced, the digital data can be reproduced without being lost. Furthermore, since double writing is recorded on separate tracks, even if an error occurs in the scan direction of the head, such as when one head is clogged, the double writing data can be played back without being lost. . For example, in FIG. 1, track b,
If track d is missing, the double-written data of A will be stored in trunk a as A1. , A2, A3 to track C. A4
is recorded, so the data can be played back without any loss.

Furthermore, since the number of times of multiplex recording can be set for each channel by the controller 15, highly reliable data can be outputted by increasing the number of times of multiplex recording for signals that require high reliability.

In the above embodiment, data subsequent to the data recorded in area 1 of the same track is recorded in area 3 for the track pattern shown in FIG. 7, but as shown in FIG. For example, when two-track interleaving is used, interleave pairs may be recorded on the same track so that interleaving is completed on one track. For example, the signal A to be written twice is Al, A2. A3. A4. ......, and if A1 and A2 and A3 and A4 are increment bears, then A is input in the area 1a of track a.
1, A2 is recorded in 3a, and A2 is recorded in area 1b of track b.
2.3b may be recorded with A1. Even with this arrangement, even if one track is missing, increment pair 0 is completed in one track, so data can be reproduced without missing data.

Further, as shown in FIG. 6, when performing multiplex recording, the data may be multiplexed on the same track. In this case, data will be lost if a large burst error occurs in the head scan direction, but data will not be lost in the case of a burst error in the tape running direction. can be realized.

Further, in the above embodiment, the case of double writing has been described, but triple writing or more may be performed depending on the importance of the data. At this time, multiple recording may be performed over two tracks or over three or more tracks.

C. Effects of the Invention] As described above, according to the present invention, the number of times of multiplex recording of data that requires high reliability when recording data is increased, multiplex recording is performed over two or more tracks,
By selecting and using the best data from among them when reproducing, there is an effect that a more reliable magnetic recording/reproducing device can be obtained.

[Brief explanation of drawings]

1 and 7 are diagrams showing trunk patterns recorded on a magnetic tape by a rotary head type multi-channel magnetic recording/reproducing apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram of this embodiment. Figure 3 is a diagram showing the relationship between input signals, memory contents, and recording signals when recording data, Figure 4 is a diagram showing the relationship between playback signals, memory contents, and output signals when reproducing data, and Figure 5. 6 is a diagram showing a track pattern of a magnetic tape in another embodiment, FIG. 6 is a track pattern diagram of a multi-channel magnetic recording/reproducing device using a helical scan method, FIG. 8 is a track configuration diagram of an 8 mm video tape, and FIG. The figure is a track configuration diagram of an 8 mm video multi-trunk PCM. 1 a-Na, I b-Nb are signal recording areas, 5
is an M-channel signal input terminal, 6 is an M-channel output terminal, 7 is a signal processing circuit, 8 is a memory that holds the signal from 1 to 2 hours, 9 is a recording amplifier, 10 is a playback amplifier and equalizer, 11 is a changeover switch , 12 is a recording/reproducing head, and 15 is a controller. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (2)

[Claims] (1) In a rotary head multi-channel magnetic recording/reproducing device that receives M (M is a positive integer) channel signals as input and is capable of recording and reproducing N (N is an integer where N>M) channel signals, any 1. A rotary head type multi-channel magnetic recording/reproducing device characterized in that the number of times of multiplex recording is changed for an input signal. (2) The rotary head type multi-channel magnetic recording and reproducing apparatus according to claim 1, wherein the input signal is multiplexed over two or more tracks.